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SURVIVAL, GROWTH, MORPHOLOGY, AND BLUE KING CRABS: EFFECT OF OCEAN ACIDIFICATION DECREASES WITH EXPOSURE TIME

Blue king crabs, Paralithodes platypus, have been an important fishery species in the Bering Sea. Large fluctuations in biomass of this species in the Pribilof Islands and the St Matthew Island regions suggests that recruitment processes are complex and are sensitive to environmental variability. In addition, there is a potential for blue king crab to be affected by decreases in ocean pH as a result of increasing atmospheric pCO2 levels, a process known as ocean acidification. In this study, juvenile blue king crabs were exposed to three pH levels in a long-term experiment to determine the effects of ocean acidification. Thirty, first crab stage juveniles were reared at ambient pH, pH 7.8, and pH 7.5 for one year. Crabs were checked daily for molts and mortalities and the morphometry and wet weight were determined after every molt. Reduced pH, particularly at the pH 7.5 level, was associated with a change is morphology, reduced growth, and increased mortality. Interestingly, the effect of pH on the mortality rate was highest at the beginning of the experiment, but declined so that at the end it was similar among the three treatments. The juveniles of other Alaskan crab species, the red king crab, Paralithodes camtschaticus, the Tanner crab, Chionoecetes bairdi, both had higher mortality rates under the same conditions indicating that blue king crab may be more resistant to ocean acidification. However, given the current low population levels in blue king crab, slower growth rates and increased juvenile mortality rates at low pH will likely lead to lower recruitment success and population level effects as ocean acidification increases in the Bering Sea.

Authors

Long, W. C., NOAA, National Marine Fisheries Service, Alaska Fisheries Science Center, USA, chris.long@noaa.gov

Van Sant, S. B., NOAA, National Marine Fisheries Service, Alaska Fisheries Science Center, USA, scott.vansant@noaa.gov

Swiney, K. M., NOAA, National Marine Fisheries Service, Alaska Fisheries Science Center, USA, katherine.swiney@noaa.gov

Foy, R. J., NOAA, National Marine Fisheries Service, Alaska Fisheries Science Center, USA, robert.foy@noaa.gov

Details

Poster presentation

Session #:056
Date: 03/01/2017
Time: 11:00 - 12:00
Location: Poster/Exhibit Hall

Presentation is given by student: No

PosterID: 469